Initial commit of llgo.
llvm-svn: 222857
diff --git a/llgo/irgen/slice.go b/llgo/irgen/slice.go
new file mode 100644
index 0000000..ee267a8
--- /dev/null
+++ b/llgo/irgen/slice.go
@@ -0,0 +1,106 @@
+//===- slice.go - IR generation for slices --------------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements IR generation for slices.
+//
+//===----------------------------------------------------------------------===//
+
+package irgen
+
+import (
+ "llvm.org/llgo/third_party/go.tools/go/types"
+ "llvm.org/llvm/bindings/go/llvm"
+)
+
+// makeSlice allocates a new slice with the optional length and capacity,
+// initialising its contents to their zero values.
+func (fr *frame) makeSlice(sliceType types.Type, length, capacity *govalue) *govalue {
+ length = fr.convert(length, types.Typ[types.Uintptr])
+ capacity = fr.convert(capacity, types.Typ[types.Uintptr])
+ runtimeType := fr.types.ToRuntime(sliceType)
+ llslice := fr.runtime.makeSlice.call(fr, runtimeType, length.value, capacity.value)
+ return newValue(llslice[0], sliceType)
+}
+
+func (fr *frame) slice(x llvm.Value, xtyp types.Type, low, high, max llvm.Value) llvm.Value {
+ if !low.IsNil() {
+ low = fr.createZExtOrTrunc(low, fr.types.inttype, "")
+ } else {
+ low = llvm.ConstNull(fr.types.inttype)
+ }
+ if !high.IsNil() {
+ high = fr.createZExtOrTrunc(high, fr.types.inttype, "")
+ }
+ if !max.IsNil() {
+ max = fr.createZExtOrTrunc(max, fr.types.inttype, "")
+ }
+
+ var arrayptr, arraylen, arraycap llvm.Value
+ var elemtyp types.Type
+ var errcode uint64
+ switch typ := xtyp.Underlying().(type) {
+ case *types.Pointer: // *array
+ errcode = gccgoRuntimeErrorARRAY_SLICE_OUT_OF_BOUNDS
+ arraytyp := typ.Elem().Underlying().(*types.Array)
+ elemtyp = arraytyp.Elem()
+ arrayptr = x
+ arrayptr = fr.builder.CreateBitCast(arrayptr, llvm.PointerType(llvm.Int8Type(), 0), "")
+ arraylen = llvm.ConstInt(fr.llvmtypes.inttype, uint64(arraytyp.Len()), false)
+ arraycap = arraylen
+ case *types.Slice:
+ errcode = gccgoRuntimeErrorSLICE_SLICE_OUT_OF_BOUNDS
+ elemtyp = typ.Elem()
+ arrayptr = fr.builder.CreateExtractValue(x, 0, "")
+ arraylen = fr.builder.CreateExtractValue(x, 1, "")
+ arraycap = fr.builder.CreateExtractValue(x, 2, "")
+ case *types.Basic:
+ if high.IsNil() {
+ high = llvm.ConstAllOnes(fr.types.inttype) // -1
+ }
+ result := fr.runtime.stringSlice.call(fr, x, low, high)
+ return result[0]
+ default:
+ panic("unimplemented")
+ }
+ if high.IsNil() {
+ high = arraylen
+ }
+ if max.IsNil() {
+ max = arraycap
+ }
+
+ // Bounds checking: 0 <= low <= high <= max <= cap
+ zero := llvm.ConstNull(fr.types.inttype)
+ l0 := fr.builder.CreateICmp(llvm.IntSLT, low, zero, "")
+ hl := fr.builder.CreateICmp(llvm.IntSLT, high, low, "")
+ mh := fr.builder.CreateICmp(llvm.IntSLT, max, high, "")
+ cm := fr.builder.CreateICmp(llvm.IntSLT, arraycap, max, "")
+
+ cond := fr.builder.CreateOr(l0, hl, "")
+ cond = fr.builder.CreateOr(cond, mh, "")
+ cond = fr.builder.CreateOr(cond, cm, "")
+
+ fr.condBrRuntimeError(cond, errcode)
+
+ slicelen := fr.builder.CreateSub(high, low, "")
+ slicecap := fr.builder.CreateSub(max, low, "")
+
+ elemsize := llvm.ConstInt(fr.llvmtypes.inttype, uint64(fr.llvmtypes.Sizeof(elemtyp)), false)
+ offset := fr.builder.CreateMul(low, elemsize, "")
+
+ sliceptr := fr.builder.CreateInBoundsGEP(arrayptr, []llvm.Value{offset}, "")
+
+ llslicetyp := fr.llvmtypes.sliceBackendType().ToLLVM(fr.llvmtypes.ctx)
+ sliceValue := llvm.Undef(llslicetyp)
+ sliceValue = fr.builder.CreateInsertValue(sliceValue, sliceptr, 0, "")
+ sliceValue = fr.builder.CreateInsertValue(sliceValue, slicelen, 1, "")
+ sliceValue = fr.builder.CreateInsertValue(sliceValue, slicecap, 2, "")
+
+ return sliceValue
+}